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B-cell maturation antigen (BCMA) is selectively expressed as a surface protein on plasma cells and is a validated target for multiple myeloma (MM). A soluble form of BCMA (sBCMA) is elevated in the sera of patients with MM. The bispecific antibodies teclistamab (BCMA×CD3) and talquetamab (G protein-coupled receptor family C group 5 member D [GPRC5D]×CD3) are in clinical development as therapies for MM. Using data from patients with relapsed/refractory MM (N=300) who participated in phase 1 studies of teclistamab (NCT03145181) or talquetamab (NCT03399799), baseline serum sBCMA levels were quantitatively analyzed relative to response to treatment, percentage of bone marrow plasma cells (BMPCs), and cytogenetic risk. By cycle 3 day 1 of treatment, sBCMA levels declined from baseline in 50 (88%) of 57 responders and 49 (98%) of 50 responders to teclistamab and talquetamab, respectively. Depth of response correlated with the magnitude of sBCMA reduction. In contrast, sBCMA increased in 33 (80%) of 41 patients and 24 (49%) of 49 patients who did not respond to teclistamab or talquetamab, respectively. Baseline sBCMA levels correlated with the percentage of BMPC; patients with extramedullary plasmacytomas who had low levels of BMPC (≤10%) tended to have high baseline sBCMA levels (≥400 ng/mL), based on limited data. Baseline sBCMA levels and changes in sBCMA levels at cycle 3 day 1 were similar in patients with high- and standard-risk cytogenetics treated with teclistamab or talquetamab. These results support the use of sBCMA as a potential surrogate marker of tumor burden and treatment response in MM.

Teclistamab (JNJ-64007957), a B-cell maturation antigen × CD3 bispecific antibody, displayed potent T-cell-mediated cytotoxicity of multiple myeloma cells in preclinical studies.A first-in-human, Phase I, dose escalation study (MajesTEC-1) is evaluating teclistamab in patients with relapsed/refractory multiple myeloma.To estimate the efficacious therapeutic dosing range of teclistamab, pharmacokinetic (PK) data following the first cycle doses in the low-dose cohorts in the Phase I study were modeled using a 2-compartment model and simulated to predict the doses that would have average and trough serum teclistamab concentrations in the expected therapeutic range (between ECThe doses predicted to have average serum concentrations between the ECOur findings show that PK simulations of early clinical data together with ex vivo cytotoxicity estimates can inform the identification of a bispecific antibody's therapeutic range.NCT03145181, date of registration: May 9, 2017.

Supplementary Legend - PDF file 66K, Supplementary legend

Purpose: To determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLT), and pharmacokinetic and pharmacodynamic profile of quisinostat, a novel hydroxamate, pan-histone deacetylase inhibitor (HDACi).Experimental Design: In this first-in-human phase I study, quisinostat was administered orally, once daily in three weekly cycles to patients with advanced malignancies, using a two-stage accelerated titration design. Three intermittent schedules were subsequently explored: four days on/three days off; every Monday, Wednesday, Friday (MWF); and every Monday and Thursday (M-Th). Toxicity, pharmacokinetics, pharmacodynamics, and clinical efficacy were evaluated at each schedule.Results: Ninety-two patients were treated in continuous daily (2–12 mg) and three intermittent dosing schedules (6–19 mg). Treatment-emergent adverse events included: fatigue, nausea, decreased appetite, lethargy, and vomiting. DLTs observed were predominantly cardiovascular, including nonsustained ventricular tachycardia, ST/T-wave abnormalities, and other tachyarhythmias. Noncardiac DLTs were fatigue and abnormal liver function tests. The maximum plasma concentration (Cmax) and area under the plasma concentration–time curve (AUC) of quisinostat increased proportionally with dose. Pharmacodynamic evaluation showed increased acetylated histone 3 in hair follicles, skin and tumor biopsies, and in peripheral blood mononuclear cells as well as decreased Ki67 in skin and tumor biopsies. A partial response lasting five months was seen in one patient with melanoma. Stable disease was seen in eight patients (duration 4–10.5 months).Conclusions: The adverse event profile of quisinostat was comparable with that of other HDACi. Intermittent schedules were better tolerated than continuous schedules. On the basis of tolerability, pharmacokinetic predictions, and pharmacodynamic effects, the recommended dose for phase II studies is 12 mg on the MWF schedule. Clin Cancer Res; 19(15); 4262–72. ©2013 AACR.

Supplementary Table 2 - PDF file 58K, A summary of PK parameters of quisinostat estimated on day 1

Supplementary Figure 1a,b - PDF file 45K, Plasma concentration-time profile of 12 mg quisinostat on (a) day 1 and (b) at steady state for MWF treatment schedule

Supplementary Table 1 - PDF file 54K, Number (percentage) of patients exhibiting increased ventricular ectopic activity

Background There is a need for novel therapies for relapsed or refractory multiple myeloma, and B-cell maturation antigen (BCMA) is a validated target. Teclistamab is a bispecific antibody that binds BCMA and CD3 to redirect T cells to multiple myeloma cells. The aim of the MajesTEC-1 study was to evaluate the safety, tolerability, and preliminary efficacy of teclistamab in patients with relapsed or refractory multiple myeloma. Methods This open-label, single-arm, phase 1 study enrolled patients with multiple myeloma who were relapsed, refractory, or intolerant to established therapies. Teclistamab was administered intravenously (range 0.3-19.2 mu g/kg [once every 2 weeks] or 19.2-720 mu g/kg [once per week]) or subcutaneously (range 80-3000 mu g/kg [once per week]) in different cohorts, with step-up dosing for 38.4 mu g/kg or higher doses. The primary objectives were to identify the recommended phase 2 dose (part one) and characterise teclistamab safety and tolerability at the recommended phase 2 dose (part two). Safety was assessed in all patients treated with at least one dose of teclistamab. Efficacy was analysed in response-evaluable patients (ie, patients who received at least one dose of teclistamab and had at least one post-baseline response evaluation). This ongoing trial is registered with ClinicalTrials.gov, NCT03145181. Findings Between June 8, 2017, and March 29, 2021, 219 patients were screened for study inclusion, and 157 patients (median six previous therapy lines) were enrolled and received at least one dose of teclistamab (intravenous n=84; subcutaneous n=73). 40 patients were administered the recommended phase 2 dose, identified as once per week subcutaneous administration of teclistamab at 1500 mu g/kg, after 60 mu g/kg and 300 mu g/kg step-up doses (median follow-up 6.1 months, IQR 3.6-8.2). There were no dose-limiting toxicities at the recommended phase 2 dose in part one. In the 40 patients treated at the recommended phase 2 dose, the most common treatment-emergent adverse events were cytokine release syndrome in 28 (70%; all grade 1 or 2 events) and neutropenia in 26 (65%) patients (grade 3 or 4 in 16 [40%]). The overall response rate in response-evaluable patients treated at the recommended phase 2 dose (n=40) was 65% (95% CI 48-79); 58% achieved a very good partial response or better. At the recommended phase 2 dose, the median duration of response was not reached. 22 (85%) of 26 responders were alive and continuing treatment after 7.1 months' median follow-up (IQR 5.1-9.1). At the recommended phase 2 dose, teclistamab exposure was maintained above target exposure levels, and consistent T-cell activation was reported. Interpretation Teclistamab is a novel treatment approach for relapsed or refractory multiple myeloma. At the recommended phase 2 dose, teclistamab showed promising efficacy, with durable responses that deepened over time, and was well tolerated, supporting further clinical development. Copyright (C) 2021 Elsevier Ltd. All rights reserved.

B-cell maturation antigen (BCMA), a member of the tumor necrosis factor family of receptors, is predominantly expressed on the surface of terminally differentiated B cells. BCMA is highly expressed on plasmablasts and plasma cells from multiple myeloma (MM) patient samples. We developed a BCMAxCD3 bispecific antibody (teclistamab [JNJ-64007957]) to recruit and activate T cells to kill BCMA-expressing MM cells. Teclistamab induced cytotoxicity of BCMA+ MM cell lines in vitro (H929 cells, 50% effective concentration [EC50] = 0.15 nM; MM.1R cells, EC50 = 0.06 nM; RPMI 8226 cells, EC50 = 0.45 nM) with concomitant T-cell activation (H929 cells, EC50 = 0.21 nM; MM.1R cells, EC50 = 0.1 nM; RPMI 8226 cells, EC50 = 0.28 nM) and cytokine release. This activity was further increased in the presence of a γ-secretase inhibitor (LY-411575). Teclistamab also depleted BCMA+ cells in bone marrow samples from MM patients in an ex vivo assay with an average EC50 value of 1.7 nM. Under more physiological conditions using healthy human whole blood, teclistamab mediated dose-dependent lysis of H929 cells and activation of T cells. Antitumor activity of teclistamab was also observed in 2 BCMA+ MM murine xenograft models inoculated with human T cells (tumor inhibition with H929 model and tumor regression with the RPMI 8226 model) compared with vehicle and antibody controls. The specific and potent activity of teclistamab against BCMA-expressing cells from MM cell lines, patient samples, and MM xenograft models warrant further evaluation of this bispecific antibody for the treatment of MM. Phase 1 clinical trials (monotherapy, #NCT03145181; combination therapy, #NCT04108195) are ongoing for patients with relapsed/refractory MM.

T-cell–mediated approaches have shown promise in myeloma treatment. However, there are currently a limited number of specific myeloma antigens that can be targeted, and multiple myeloma (MM) remains an incurable disease. G-protein–coupled receptor class 5 member D (GPRC5D) is expressed in MM and smoldering MM patient plasma cells. Here, we demonstrate that GPRC5D protein is present on the surface of MM cells and describe JNJ-64407564, a GPRC5DxCD3 bispecific antibody that recruits CD3+ T cells to GPRC5D+ MM cells and induces killing of GPRC5D+ cells. In vitro, JNJ-64407564 induced specific cytotoxicity of GPRC5D+ cells with concomitant T-cell activation and also killed plasma cells in MM patient samples ex vivo. JNJ-64407564 can recruit T cells and induce tumor regression in GPRC5D+ MM murine models, which coincide with T-cell infiltration at the tumor site. This antibody is also able to induce cytotoxicity of patient primary MM cells from bone marrow, which is the natural site of this disease. GPRC5D is a promising surface antigen for MM immunotherapy, and JNJ-64407564 is currently being evaluated in a phase 1 clinical trial in patients with relapsed or refractory MM (NCT03399799).

CD33 is expressed in 90% of patients with acute myeloid leukemia (AML), and its extracellular portion consists of a V domain and a C2 domain. A recent study showed that a single nucleotide polymorphism (SNP), rs12459419 (C > T), results in the reduced expression of V domain–containing CD33 and limited efficacy of V domain–binding anti-CD33 antibodies. We developed JNJ-67571244, a novel human bispecific antibody capable of binding to the C2 domain of CD33 and to CD3, to induce T-cell recruitment and CD33+ tumor cell cytotoxicity independently of their SNP genotype status. JNJ-67571244 specifically binds to CD33-expressing target cells and induces cytotoxicity of CD33+ AML cell lines in vitro along with T-cell activation and cytokine release. JNJ-67571244 also exhibited statistically significant antitumor activity in vivo in established disseminated and subcutaneous mouse models of human AML. Furthermore, this antibody depletes CD33+ blasts in AML patient blood samples with concurrent T-cell activation. JNJ-67571244 also cross-reacts with cynomolgus monkey CD33 and CD3, and dosing of JNJ-67571244 in cynomolgus monkeys resulted in T-cell activation, transient cytokine release, and sustained reduction in CD33+ leukocyte populations. JNJ-67571244 was well tolerated in cynomolgus monkeys up to 30 mg/kg. Lastly, JNJ-67571244 mediated efficient cytotoxicity of cell lines and primary samples regardless of their SNP genotype status, suggesting a potential therapeutic benefit over other V-binding antibodies. JNJ-67571244 is currently in phase 1 clinical trials in patients with relapsed/refractory AML and high-risk myelodysplastic syndrome.

Acute myeloid leukemia (AML) is a heterogeneous disease characterized by uncontrolled clonal expansion of hematopoietic progenitor cells (myeloid blasts). Disease remission can be achieved with standard induction chemotherapy, but refractory and relapsed disease remains a challenge with a 5-year overall survival rate of approximately 25%. Induction of differentiation is an alternative approach to AML therapy. Dihydroorotate dehydrogenase (DHODH) catalyzes the ubiquinone-mediated oxidation of dihydroorotate (DHO) to orotate in the de novo pyrimidine synthesis pathway. Pre-clinical findings demonstrated that DHODH is a metabolic vulnerability in AML and a new target for differentiation therapy. Given the genetic complexity of myeloid malignancies, future use of DHODH inhibitors in combination with selected antineoplastic agents (e.g., azacitidine) with nonoverlapping mechanisms of action may address specific aspects of the complex pathogenesis of AML and MDS (myelodysplastic syndrome), ultimately improving patients' outcomes.JNJ74856665 is an orally available, potent and selective DHODH inhibitor. JNJ-74856665 inhibited the biochemical activity of human DHODH with a 50% inhibitory concentration (IC50) in the subnanomolar range and in vitro inhibited proliferation of MOLM-13, OCI-AML3, HL60 and THP-1 AML cell lines with low nanomolar IC50 values. Mechanism of action studies using these four cell lines demonstrated induction of CD11b and CD14 differentiation marker mRNA levels. Differentiation was accompanied by cell cycle arrest and apoptosis induction. Importantly, addition of excess uridine to the tissue culture conditions abrogated the anti-proliferative, differentiation and apoptosis inducing activity of JNJ-74856665, indicating on target activity. In vivo, JNJ-74856665 mediated significant activity in decreasing leukemic burden and increasing life span across subcutaneous (MOLM-13 and OCI-AML3) and disseminated (MOLM-13) xenografts, respectively. Pharmacodynamic investigations demonstrated target engagement as evidenced by upregulation of the DHODH substrate dihydroorotate in plasma and induction of differentiation markers in tumor. Combination of JNJ-74856665 with azacitidine in vivo demonstrated lack of antagonism in the anti-leukemic activity.The results described herein demonstrate that JNJ-74856665 exerts potent anti-leukemic activity in vitro and in vivo and warrant further investigation. To that end, a phase 1 clinical trial assessing the safety and efficacy of JNJ-74856665 in patients with AML and MDS is planned to initiate shortly. Citation Format: Christine Pietsch, Scott Kuduk, Xiaochun Zhang, Tammy Bush, Faraz Kazmi, Edgar Jacoby, Zhuming Zhang, Lindsey DeRatt, Weixue Wang, Aaron Patrick, Andrew Steele, Friedericke Pastore, Tony Greway, Nikki Daskalakis, Kathryn Bradford, Kathryn Packman, Gilles Bignan, James Edwards, Ricardo Attar, Yusri Elsayed, Jacqueline Bussolari, Ulrike Philippar. JNJ-74856665, a novel DHODH inhibitor, mediates potent anti-leukemic activity and differentiation in vitro and in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1256.

Background: Constitutive activation of the classical nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB) pathway is a clear driver of B-cell non-Hodgkin lymphomas (NHL). Bruton's Tyrosine Kinase (BTK) and Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), which lies downstream of BTK, are key mediators of the classical NF-κB signaling pathway activated by BCR and TCR receptors. JNJ-67856633 is a first-in-class MALT1 protease inhibitor. JNJ-64264681 is a BTK inhibitor with improved selectivity against BTK. Blocking the BCR pathway at multiple points using these two orally bioavailable compounds could enhance clinical activity in B-cell lymphoma patients. Methods: JNJ-67856633 and JNJ-64264681 are currently being evaluated in phase 1 clinical trials designed to establish safety, PK, PD and the Recommended Phase 2 Dose (RP2D) of each agent. Results: JNJ-67856633 is a potent, selective, orally bioavailable, allosteric inhibitor of MALT1 protease activity. The compound inhibits proliferation of activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL) cell lines bearing CD79b or CARD11 mutations as well as models mimicking resistance to covalent BTK inhibitors. JNJ-67856633 exhibits potent tumor growth inhibition in two human DLBCL xenograft models, OCI-Ly3 and OCI-Ly10, and mutation selected patient derived DLBCL xenografts. Furthermore, treatment with JNJ-67856633 leads to dose dependent inhibition of the generation of Tregs (CD4+CD25+FoxP3+) following CD3/28 stimulation in vitro, suggesting a potential immune modulatory role of MALT1 inhibition. JNJ-64264681 is an orally active small molecule that is a potent, selective, and irreversible covalent BTK inhibitor. JNJ-64264681 inhibits the growth of CD79b-mutant DLBCL cell lines in vitro and potently inhibits tumor growth in xenograft- or patient-derived DLBCL models in vivo. Treatment with JNJ-64264681 and JNJ-67856633 administered together demonstrated statistically significant tumor growth inhibition compared with vehicle control in two CD79b mutant mouse lymphoma models, one based on a DLBCL cell line (OCI-Ly10) and one based on a patient-derived DLBCL model (LY2298). In both models, the combination showed increased growth inhibition compared with single agents and tumor regression in the combination arm. Synergistic anti-proliferative activity was observed in three DLBCL cell lines carrying CD79b mutations and one MCL cell line. Conclusions: Taken together, the in vitro and in vivo data for JNJ-67856633 and JNJ-64264681 suggest that combination therapy can increase the anti-tumor effect of the monotherapies and provide a more sustained response, offering strong support for clinical investigation of the combination of these two novel agents. A phase 1b combination study is scheduled to initiate. Citation Format: Ulrike Philippar, Lorena Fontan, Ivo Cornelissen, Haopeng Rui, Sriram Balasubramanian, Marcello Gaudiano, Mariette Bekkers, Luc Van Nuffel, Tianbao Lu, Tianbao Lu, John Wiener, Mark Tichenor, Tony Greway, Kathryn Packman, Bie Verbist, Yusri Elsayed, Ricardo Attar, Jacqueline Bussolari, John Gerecitano. Combination therapy of JNJ-67856633, a novel, first-in-class MALT1 protease inhibitor, and JNJ-64264681, a novel BTK inhibitor, for the treatment of B-cell lymphomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1267.

Background: Quisinostat is a hydroxamate, second-generation, orally available pan-histone deacetylase inhibitor. Objectives: To evaluate the efficacy and safety of oral quisinostat in patients with previously treated cutaneous T-cell lymphoma (CTCL). Methods: Patients received quisinostat 8 mg or 12 mg on days 1, 3 and 5 of each week in 21-day treatment cycles. Primary efficacy end point was cutaneous response rate (RR) based on the modified Severity Weighted Assessment Tool (mSWAT). Secondary end points included global RR, duration of response (DOR) in skin, progression-free survival (PFS), pruritus relief, safety and pharmacodynamic markers. Results: Eight of 26 (25 evaluable) patients achieved ≥ 50% reduction in mSWAT score at least once, with confirmed cutaneous response in six (RR 24%). There was a low global RR of 8%. DOR in skin ranged from 2·8 to 6·9 months. Median PFS was 5·1 months. Pruritus relief was more frequent in cutaneous responders (67%) than nonresponders (32%). Serial tumour biopsies revealed an increase in acetylated tubulin, indicating a target effect of histone deacetylase 6. Twenty-one of 26 (81%) patients were withdrawn from the study before or at clinical cut-off; five (19%) continued to receive treatment with quisinostat. The most common drug-related adverse events were nausea, diarrhoea, asthenia, hypertension, thrombocytopenia and vomiting. Grade 3 drug-related adverse events included hypertension, lethargy, pruritus, chills, hyperkalaemia and pyrexia. Conclusions: Quisinostat 12 mg three times weekly is active in the treatment of patients with relapsed or refractory CTCL, with an acceptable safety profile. Combination therapy with other drugs active in CTCL may be appropriate.

B cell maturation antigen (BCMA; CD269; TNFRSF17) is a surface receptor, expressed on benign and malignant plasma cells. The restricted expression of BCMA on B-cell lineage makes it an ideal target for multiple myeloma (MM) immunotherapy. BCMAxCD3 bispecific antibody (Teclistamab; JNJ-64007957) has been developed to recruit CD3+ T-cells to BCMA+ MM cells. Teclistamab demonstrated potent cytotoxicity in a murine xenograft model and against ex vivo primary MM cells. Teclistamab clinical starting dose in the first in human (FIH) study in relapsed refractory MM patients began at the minimal anticipated biological effect level (MABEL) of 0.3 µg/kg using the EC20 of the in vitro cytotoxicity assay in the purified T cells model with MM.1R cell line. Since the MABEL dose is usually low, it is important to have guidance on the expected therapeutic range in patients. The therapeutic concentrations of teclistamab were estimated from an ex vivo cytotoxicity assay in which samples from MM patients (frozen purified mononuclear cells from bone marrow) were treated with healthy human purified T cells (1:1 ratio) spiked with teclistamab and incubated for 48 hours. The mean and range of EC50 and EC90 values of the cytotoxicity endpoint were estimated. The pharmacokinetic (PK) data following the first cycle doses in the low dose cohorts in the FIH study in MM patients were modeled using 2-compartment model and simulated to predict the doses that will have average and trough serum teclistamab concentrations in the expected therapeutic range (between EC50 and EC90). The predicted doses with average serum concentrations between the mean EC50 (372 ng/mL) and mean EC90 (2287 ng/mL) range were validated with the observed clinical data showing positive response in 2 out of 4 patients at the 38.4 µg/kg intravenous treatment dose level and their average serum teclistamab concentration overlaid within the estimated therapeutic range. This was also confirmed with the teclistamab concentrations in bone marrow samples (measured in a subset of MM patients in the study) where they were found to superimpose in the estimated therapeutic range. In addition, simulations predicted the dose that will have trough levels above the maximum EC90 (6070 ng/mL), to account for patients with high tumor burden, at which the observed clinical data have shown promising response rate and has been selected to be the recommended subcutaneous phase 2 dose of 1500 µg/kg. In conclusion, ex vivo cytotoxicity assay with MM patients bone marrow samples is an informative tool to predict the efficacious serum concentration of immuno-oncology drugs in MM patients. PK modeling and simulations of MM patients' data in FIH study coupled with the ex vivo cytotoxicity estimates provided guidance on the expected recommended phase 2 dose during the escalation phase of the FIH study. Disclosures Girgis: Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company. Wang Lin:Johnson & Johnson: Current Employment. Pillarisetti:Johnson & Johnson: Current Employment. Banerjee:Janssen: Current Employment. Goldberg:Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company. Shetty:Johnson & Johnson: Current Employment. Stephenson:Johnson & Johnson: Current Employment, Current equity holder in private company. Hilder:Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company. Hanna:Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company. Smit:Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company. Adams III:Genmab: Current Employment. Sun:Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company. Infante:Janssen: Current Employment. Elsayed:Johnson & Johnson: Current Employment. Sharma:Johnson & Johnson: Current Employment.

Introduction: Constitutive activation of the classical nuclear factor kappa-light-chain-enhancer of activated B cells (NF κB) pathway is a clear driver of B-cell lymphomas, especially the aggressive activated B-cell (ABC) subtype of diffuse large B-cell lymphoma (DLBCL). Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is a key mediator of the classical NF-κB signaling pathway downstream of B-cell receptor and T-cell receptor. MALT1 possesses two functions: a scaffolding function to recruit NF-κB signaling proteins and a protease function to cleave and inactivate inhibitors of the NF-κB signaling pathway. Methods: Using a high-throughput screen followed by iterative structure-activity relationship (SAR) analyses, the MALT1 inhibitor JNJ-67856633 was identified. JNJ-67856633 was evaluated using biochemical, cellular in vitro, in vivo tumor efficacy and safety models. Results: JNJ-67856633 is a potent, selective, allosteric inhibitor of MALT1 protease activity as measured by biochemical assays or downstream cellular cytokine readouts (IL6/10) or direct MALT1 substrate cleavage (RelB, BCL10). The compound inhibits proliferation of activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL) cell lines bearing CD79b or CARD11 mutations as well as models mimicking resistance to covalent Bruton's tyrosine kinase (BTK) inhibitors. Furthermore, combination effects were observed in CD79b cellular ABC-DLBCL models when JNJ-67856633 was combined with a BTK inhibitor. JNJ-67856633 showed activity in organoid cultures derived from ABC-DLBCL patients. JNJ-67856633 leads to potent in vivo pharmacodynamic shutdown in CD79b- as well as CARD11-mutant ABC-DLBCL models as measured by serum IL10 or uncleaved BCL10 levels in tumors. JNJ-67856633 exhibits potent tumor growth inhibition in two human DLBCL xenograft models, OCI Ly3 and OCI Ly10. In addition, >5 patient-derived DLBCL xenografts were evaluated and activity in mutation selected models was observed. To address the role of MALT1 inhibition in T cells, primary human T cells derived from normal healthy volunteers were treated with JNJ-67856633 in vitro. Dose-dependent inhibition of the generation of Tregs (CD4+CD25+FoxP3+) following CD3/28 stimulation was observed upon treatment with JNJ-67856633, suggesting a potential immune-modulatory role of MALT1 inhibition. Conclusions: Phase 1 clinical trials assessing the safety and efficacy of JNJ-67856633 initiated in 2019. JNJ-67856633 is a combination partner for BTK inhibitors and a promising treatment option for BTKi-resistant tumors, with demonstrated preclinical activity in CARD11 mutant tumors. In addition to ABC-DLBCL, a MALT1 inhibitor is a promising treatment option for patients with CLL, MCL, WM, and FL whose tumors have been shown to be sensitive to inhibition of BTK. MALT lymphomas, characterized by MALT1 and BCL10 translocation, represent another attractive target for MALT1 inhibition. Citation Format: Ulrike Philippar, Tianbao Lu, Lorena Fontan, Nele Vloemans, Mariette Bekkers, Luc van Nuffel, Marcello Gaudiano, Katarzyna Wnuk-Lipinska, Bas-Jan Van Der Leede, Katie Amssoms, Kristof Kimpe, Bart Medaer, Tony Greway, Yann Abraham, Max Cummings, Emanuele Trella, Greet Vanhoof, Weimei Sun, Jan Willem Thuring, Peter Connolly, Haopeng Rui, Sriram Balasubramanian, John Gerecitano, Ari Melnick, Ricardo Attar. Discovery of JNJ-67856633: A novel, first-in-class MALT1 protease inhibitor for the treatment of B-cell lymphomas [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-49.

Introduction: Constitutive activation of the classical nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB) pathway is a clear driver of B-cell lymphomas, especially the aggressive activated B-cell (ABC) subtype of diffuse large B-cell lymphoma (DLBCL). Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is a key mediator of the classical NF-κB signaling pathway downstream of B-cell receptor and T-cell receptor. MALT1 possesses 2 functions: a scaffolding function to recruit NF-κB signaling proteins and a protease function to cleave and inactivate inhibitors of the NF-κB signaling pathway. Methods: Using a high-throughput screen followed by iterative structure-activity relationship (SAR) analyses, the MALT1 inhibitor JNJ-67856633 was identified. The lead compound was evaluated using biochemical, in vitro cellular and in vivo tumor efficacy and safety models. Results: JNJ-67856633 is a potent, selective, allosteric inhibitor of MALT1 protease activity as measured by biochemical assays or downstream cellular cytokine readouts (IL 6/10) or direct MALT1 substrate cleavage (RelB, BCL10). The compound inhibits proliferation of activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL) cell lines bearing CD79b or CARD11 mutations as well as models mimicking resistance to covalent Bruton's Tyrosine Kinase (BTK) inhibitors. Furthermore, combination effects were observed in CD79b cellular ABC-DLBCL models when JNJ-67856633 was combined with a BTK inhibitor. JNJ-67856633 leads to potent in vivo pharmacodynamic shutdown in CD79b- as well as CARD11-mutant ABC-DLBCL models as measured by serum IL10 or uncleaved BCL10 levels in tumors. JNJ-67856633 exhibits potent tumor growth inhibition in two human DLBCL xenograft models, OCI Ly3 and OCI Ly10, and mutation selection patient derived DLBCL xenografts. To address the role of MALT1 inhibition in T cells, primary human T cells derived from normal healthy volunteers were treated with JNJ-67856633 in vitro. Dose dependent inhibition of the generation of Tregs (CD4+CD25+FoxP3+) following CD3/28 stimulation was observed upon treatment with JNJ-67856633 suggesting a potential immune modulatory role of MALT1 inhibition. Conclusions: Phase 1 clinical trials assessing the safety and efficacy of JNJ-67856633 initiated in 2019. JNJ-67856633 is a combination partner for BTK inhibitors and a promising treatment option for BTKi-resistant tumors, with demonstrated preclinical activity in CARD11 mutant tumors. In addition to ABC-DLBCL, a MALT1 inhibitor is a promising treatment option for patients with CLL, MCL, WM, and FL whose tumors have been shown to be sensitive to inhibition of BTK. MALT lymphomas, characterized by MALT1 and BCL10 translocation, represent another attractive target for MALT1 inhibition. Citation Format: Ulrike Philippar, Tianbao Lu, Nele Vloemans, Mariette Bekkers, Luc Van Nuffel, Marcello Gaudiano, Katarzyna Wnuk-Lipinska, Bas-jan Van Der Leede, Katie Amssoms, Kristof Kimpe, Bart Medaer, Tony Greway, Yann Abraham, Max Cummings, Emanuele Trella, Greet Vanhoof, Weimei Sun, Jan Willem Thuring, Peter Connolly, Jan Linders, Haopeng Rui, Sriram Balasubramanian, Amy Johnson, John Gerecitano, Jenna Goldberg, James P. Edwards, Yusri Elsayed, Jennifer Smit, Jaqueline Bussolari, Jaqueline Bussolari, Ricardo Attar. Discovery of JNJ-67856633: A novel, first-in-class MALT1 protease inhibitor for the treatment of B cell lymphomas [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5690.

CD33 is expressed in 90% of acute myeloid leukemia (AML) patients with expression in both blasts and leukemic stem cells. The extracellular portion of CD33 consists of a V and a C2 Ig-like domain. A recent study showed that a single nucleotide polymorphism (SNP) rs12459419 (C >T; Ala14Val in exon 2 of CD33) was present in ~50% of the Western AML population and is associated with preferential expression of an alternatively spliced CD33 isoform lacking exon2, resulting in the deletion of the CD33 V domain. Interestingly, several CD33-antibody-based therapies, including gemtuzumab ozogamicin (GO), the only approved anti-CD33 antibody drug conjugate for AML, bind and recognize the V domain of CD33. Recent data demonstrated that patients with SNP rs12459419 CC genotype receiving GO had a significantly lower risk of relapse and increased event-free survival compared to patients with the CT or TT genotypes. Given the data with GO, it is reasonable to hypothesize that the activity of other V binding CD33 antibodies maybe limited to a subset (~50%, rs12459419 CC genotype) of AML patients. On the other hand, since the C2 domain is shared by all CD33 isoforms in AML patients, we hypothesized that a C2 binding anti-CD33 antibody could target AML cells more broadly regardless of their SNP status. Additionally, we reasoned that targeting the membrane proximal C2 domain would be a beneficial strategy for a CD3 redirection bispecific antibody as targeting epitopes closer to the membrane have been reported to mediate efficient synapse formation between T cells and target cells leading to potent anti-tumor responses. We developed JNJ-67571244, a novel human bispecific antibody capable of binding to the C2 domain of CD33, and to CD3 to induce T-cell recruitment and tumor cell cytotoxicity independently of their SNP status. JNJ-67571244 specifically binds to CD33-expressing target cells and induces cytotoxicity of CD33+ AML cell lines in vitro at 48 hours (EC50 values: KG-1=0.168 nM, MOLM-13=0.131 nM, Kasumi-1=0.05 nM and OCI-AML3=0.183 nM) with concomitant T cell activation (EC50 values: KG-1=0.066 nM, MOLM-13=0.028 nM, Kasumi-1=0.043 nM and OCI-AML3=0.05 nM) along with cytokine release. In contrast, JNJ-67571244 was unable to kill CD33- cancer cell lines (CARNAVAL and KG-1 cells with a genetic deletion of CD33), demonstrating the specificity of the cytotoxicity. JNJ-67571244 demonstrated statistically significant anti-tumor activity in vivo in established disseminated and subcutaneous mouse models of human AML (MOLM-13Luc and KG-1: up to 100% and 92% tumor growth inhibition respectively) through T cell redirection activity. Furthermore, this antibody could deplete CD33+ blasts (EC50=0.549 nM) in AML patient blood samples (n=7) in an ex-vivo assay at 48 hours with concurrent T cell activation (EC50=0.355 nM). JNJ-67571244 also cross-reacts with cyno CD33 and CD3 and was well-tolerated in cynomolgus monkeys up to 30 mg/kg along with a sustained reduction in CD33+ leukocyte populations. Lastly, JNJ-67571244 mediated efficient cytotoxicity of cell lines and primary samples regardless of their genotype status (SNP rs12459419 CC, CT and TT), suggesting a potential therapeutic advantage over competitor V-binding antibodies. JNJ-67571244 is currently in Phase 1 clinical trials to treat relapsed/refractory AML and high risk myelodysplastic syndrome (MDS) patients (NCT03915379). Citation Format: Priyanka Nair-Gupta, Michael Diem, Dara Reeves, Weirong Wang, Robert Schulingkamp, Katrin Sproesser, Bethany Mattson, Bradley Heidrich, Jocelin Joseph, Jocelyn Sendecki, Brad Foulk, Gerald Chu, Damien Fink, Qun Jiao, Sheng-Jiun Wu, Kathryn Packman, Yusri Elsayed, Ricardo Attar, Francois Gaudet. JNJ-67571244: A novel anti-CD33 C2 domain binding bispecific antibody with potent T cell redirection activity [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5662.

100 Background: Teclistamab (JNJ-64007957) is a bispecific BCMA x CD3 antibody that induces T cell-mediated cytotoxicity against BCMA-expressing myeloma cells. Initial results from an ongoing study of teclistamab in RRMM (NCT03145181) are presented. Methods: Pts have MM and are RR to standard therapies. Primary objective for part 1 is to identify a recommended phase 2 dose(s). Multiple intravenous (iv) doses ± priming doses were explored. Adverse events (AEs) were graded per CTCAE v4.03 and cytokine release syndrome (CRS) per Lee et al 2014. Response was investigator-assessed using IMWG criteria; minimal residual disease (MRD) in bone marrow was assessed by next generation sequencing. Results: As of 31 Jan 2020, 66 pts had received iv teclistamab (0.3–270 µg/kg). Median age was 64 y (24–82), median prior therapies was 6 (2–14), 97% triple-class exposed, 83% triple-class refractory, and 38% penta-drug refractory. Most common treatment-related AEs (all grade) were CRS (56%), neutropenia (26%), and anemia (23%). CRS events were all grade 1–2 and generally confined to initial doses. 8% of pts had treatment-related neurotoxicity (3% grade ≥3), and 9% had infusion related reaction. Infection-related AEs were reported in 61% of pts (21% grade ≥3). 2 dose-limiting toxicities were reported: grade 4 delirium (resolved after 16 days) and grade 4 thrombocytopenia (resolved after 1 day). 36% of pts had treatment-related grade ≥3 AEs; neutropenia (20%) and anemia (14%) were most frequent. Only 1 grade 5 AE was reported (respiratory failure in the setting of pneumonia deemed unrelated by the investigator). PK results indicate that the half-life of teclistamab supports weekly dosing. On-target pharmacodynamic activity (T cell redistribution and activation along with transient release of cytokines) was observed at doses ≥9.6 µg/kg. Cytokine production was modulated with step-up dosing while T cell activation was maintained. 65 pts were evaluable for response. Activity was observed starting at treatment doses ≥38.4 µg/kg, with 20/52 (38%) pts achieving a response. At the highest dose, 7/9 (78%) pts responded (1 response pending confirmation). Of MRD-evaluable pts who had complete response, 2/2 were MRD negative at 10−6 with treatment ongoing > 12 mo. Conclusions: Teclistamab has manageable safety across all doses explored. A 78% overall response rate was observed at the highest weekly treatment dose in pts with advanced RRMM, supporting further evaluation of teclistamab in expansion cohorts. Clinical trial information: NCT03145181.

Purpose: To determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLT), and pharmacokinetic and pharmacodynamic profile of quisinostat, a novel hydroxamate, pan-histone deacetylase inhibitor (HDACi). Experimental Design: In this first-in-human phase I study, quisinostat was administered orally, once daily in three weekly cycles to patients with advanced malignancies, using a two-stage accelerated titration design. Three intermittent schedules were subsequently explored: four days on/three days off; every Monday, Wednesday, Friday (MWF); and every Monday and Thursday (M-Th). Toxicity, pharmacokinetics, pharmacodynamics, and clinical efficacy were evaluated at each schedule. Results: Ninety-two patients were treated in continuous daily (2–12 mg) and three intermittent dosing schedules (6–19 mg). Treatment-emergent adverse events included: fatigue, nausea, decreased appetite, lethargy, and vomiting. DLTs observed were predominantly cardiovascular, including nonsustained ventricular tachycardia, ST/T-wave abnormalities, and other tachyarhythmias. Noncardiac DLTs were fatigue and abnormal liver function tests. The maximum plasma concentration (Cmax) and area under the plasma concentration–time curve (AUC) of quisinostat increased proportionally with dose. Pharmacodynamic evaluation showed increased acetylated histone 3 in hair follicles, skin and tumor biopsies, and in peripheral blood mononuclear cells as well as decreased Ki67 in skin and tumor biopsies. A partial response lasting five months was seen in one patient with melanoma. Stable disease was seen in eight patients (duration 4–10.5 months). Conclusions: The adverse event profile of quisinostat was comparable with that of other HDACi. Intermittent schedules were better tolerated than continuous schedules. On the basis of tolerability, pharmacokinetic predictions, and pharmacodynamic effects, the recommended dose for phase II studies is 12 mg on the MWF schedule. Clin Cancer Res; 19(15); 4262–72. ©2013 AACR.

Purpose: Identify subgroups of patients with relapsed/refractory follicular lymphoma deriving substantial progression-free survival (PFS) benefit with bortezomib–rituximab versus rituximab in the phase III LYM-3001 study. Experimental Design: A total of 676 patients were randomized to five 5-week cycles of bortezomib–rituximab or rituximab. The primary end point was PFS; this prespecified analysis of candidate protein biomarkers and genes was an exploratory objective. Archived tumor tissue and whole blood samples were collected at baseline. Immunohistochemistry and genetic analyses were completed for 4 proteins and 8 genes. Results: In initial pairwise analyses, using individual single-nucleotide polymorphism genotypes, one biomarker pair (PSMB1 P11A C/G heterozygote, low CD68 expression) was associated with a significant PFS benefit with bortezomib–rituximab versus rituximab, controlling for multiple comparison corrections. The pair was analyzed under dominant, recessive, and additive genetic models, with significant association with PFS seen under the dominant model (G/G+C/G). In patients carrying this biomarker pair [PSMB1 P11A G allele, low CD68 expression (≤50 CD68-positive cells), population frequency: 43.6%], median PFS was 14.2 months with bortezomib–rituximab versus 9.1 months with rituximab (HR 0.47, P < 0.0001), and there was a significant overall survival benefit (HR 0.49, P = 0.0461). Response rates were higher and time to next antilymphoma therapy was longer in the bortezomib–rituximab group. In biomarker-negative patients, no significant efficacy differences were seen between treatment groups. Similar proportions of patients had high-risk features in the biomarker-positive and biomarker-negative subsets. Conclusions: Patients with PSMB1 P11A (G allele) and low CD68 expression seemed to have significantly longer PFS and greater clinical benefit with bortezomib–rituximab versus rituximab. Clin Cancer Res; 19(9); 2551–61. ©2013 AACR.

International audience; In recent years, the number of approved and investigational agents that can be safely administered for the treatment of lymphoma patients for a prolonged period of time has substantially increased. Many of these novel agents are evaluated in early-phase clinical trials in patients with a wide range of malignancies, including solid tumors and lymphoma. Furthermore, with the advances in genome sequencing, new "basket" clinical trial designs have emerged that select patients based on the presence of specific genetic alterations across different types of solid tumors and lymphoma. The standard response criteria currently in use for lymphoma are the Lugano Criteria which are based on 18-Fluoro-deoxyglucose positron emission tomography (FDG-PET) or bidimensional tumor measurements on computerized tomography (CT) scans. These differ from the RECIST criteria used in solid tumors, which use unidimensional measurements. The RECIL group hypothesized that single dimension measurement could be used to assess response to therapy in lymphoma patients, producing results similar to the standard criteria. We tested this hypothesis by analyzing 47,828 imaging measurements from 2983 individual adult and pediatric lymphoma patients enrolled on 10 multicenter clinical trials, and developed new lymphoma response criteria (RECIL 2017). We demonstrate that assessment of tumor burden in lymphoma clinical trials can use the sum of longest diameters of a maximum of three target lesions. Furthermore, we introduced a new provisional category of a minor response. We also clarified response assessment in patients receiving novel immune therapy and targeted agents that generate unique imaging situations.

Background CC-chemokine ligand 2 (CCL2) promotes tumor growth by angiogenesis, macrophage infiltration and tumor invasion, and distant metastasis. Carlumab (CNTO 888) is a human IgG1κ mAb with high affinity and specificity for human CCL2. Preclinical data suggest carlumab may offer clinical benefit to cancer patients. Methods In a phase 2, open-label study, patients with metastatic castration-resistant prostate cancer (CRPC) previously treated with docetaxel received a 90-min infusion of 15 mg/kg carlumab q2w. The primary endpoint was response rate: change from baseline in skeletal lesions, extraskeletal lesions, and PSA values. Secondary endpoints included overall response rate (CR + PR) by RECIST, OS, PSA response, safety, pharmacodynamics, pharmacokinetics, immunogenicity. Results Forty-six patients were treated with 6 median (range 1, 26) doses. One patient had SD >6 months. There were no PSA or RECIST responses. Fourteen (34 %) patients had SD ≥3 months. Median OS was 10.2 (95 % CI: 5.2, not estimable) months. Twelve (39 %) patients reported improved pain scores. AEs occurred in 43 (93 %) patients, including 27 (59 %) with grade ≥3 AEs. Common grade ≥3 AEs were back (11 %) and bone (9 %) pain. Twenty (43 %) patients experienced SAEs, including pneumonia, spinal cord compression, back pain. No patient developed antibodies to carlumab. Steady-state serum concentrations were achieved after 3 repeated doses and were above the 10-μg/mL target concentration. Suppression of free CCL2 serum concentrations was briefly observed following each dose but was not sustained. Conclusion Carlumab was well-tolerated but did not block the CCL2/CCR2 axis or show antitumor activity as a single agent in metastatic CRPC.

Background: Bortezomib is approved for the treatment of multiple myeloma and a role has been suggested in the treatment of systemic AL amyloidosis (AL). Methods: In this phase 1 dose-escalation portion of the first prospective study of single-agent bortezomib in AL, 31 patients with relapsed disease, including 14 (45%) with cardiac involvement, received bortezomib in seven dose cohorts on once-weekly (0.7, 1.0, 1.3, 1.6 mg/m2) and twice-weekly (0.7, 1.0, 1.3 mg/m2) schedules. Electrocardiographic, Holter and echocardiographic studies were evaluated in all patients to determine safety and response. Results: During therapy (median treatment period 210 days), no patient developed significant ventricular or supraventricular rhythm disturbance on 24-h Holter monitoring; however, no patient satisfied study criteria for cardiac response using echocardiographic assessment or New York Heart Association classification. Seven patients (23%) had a ≥10% fall in left ventricular ejection fraction, but only one met criteria for cardiac deterioration. The predominant cardiac adverse events were peripheral edema (23%), orthostatic hypotension (13%) and hypotension (10%). Two patients developed grade 3 congestive heart failure, which resolved following treatment interruption. In this Phase 1 portion, the maximum tolerated dose of bortezomib on either schedule was not reached. Hematologic responses occurred in 14 patients (45%), including seven (23%) complete responses. In non-responders mean left ventricular wall thickness increased during the course of treatment. Conclusions: AL is frequently rapidly progressive; in these patients who had relapsed or progressed following previous conventional therapies, these results suggest that bortezomib may slow the progression of cardiac amyloid with limited toxicity.

New treatment options are required for primary systemic AL amyloidosis (AL). This phase 1 dose-escalation component of a phase 1/2 study in relapsed AL aimed to determine the maximum tolerated dose (MTD) of bortezomib once weekly (0.7-1.6 mg/m2; days 1, 8, 15, and 22; 35-day cycles) and twice weekly (0.7-1.3 mg/m2; days 1, 4, 8, and 11; 21-day cycles) and assess preliminary hematologic responses. Thirty-one patients with relapsed AL were enrolled across 7 cohorts. Dose-limiting toxicity included grade 3 congestive heart failure in 2 patients (1 at once weekly, 1.6 mg/m2, and 1 at twice weekly, 1.0 mg/m2). MTD was not defined for either schedule; the maximum doses of 1.6 mg/m2 (once weekly) and 1.3 mg/m2 (twice weekly) are being used in phase 2 evaluation. Most commonly reported toxicities on both schedules included gastrointestinal events, fatigue, and nervous system disorders. Discontinuations and dose reductions for toxicity were reported in 12 and 4 patients, respectively. No treatment-related deaths occurred. Hematologic responses occurred in 15 (50%) of 30 evaluable patients, including 6 (20%) complete responses. Median time to first response was 1.2 months. Once-weekly and twice-weekly bortezomib appear generally well tolerated in relapsed AL, with promising hematologic responses. This study is registered with http://ClinicalTrials.gov under identifier NCT00298766.

B-cell maturation antigen (BCMA) is a tumor necrosis factor (TNF) family surface protein predominantly expressed on terminally differentiated B-cells. BCMA signals through P38/NF-κB pathway upon binding to its ligands; a proliferation inducing ligand (APRIL) and B-cell activator of the TNF family (BAFF) and promote anti-apoptotic gene expression. BCMA expression is elevated in plasma blasts, plasma cells from spleen and bone marrow and correlates with disease progression in multiple myeloma (MM). BCMA expression in premalignant MM settings such as monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) also gives an opportunity for early cancer interception. To target cancer cells expressing BCMA, we developed a BCMAxCD3 bispecific antibody using the Genmab DuoBody® technology (Ab-957) to recruit T cells to BCMA-expressing MM cells so that T cells could be activated and induced to kill BCMA+ cancer cells. This antibody can induce cytotoxicity of BCMA+ MM cell lines in vitro (H929 cells: EC50=0.15nM, MM1.R cells: EC50=0.06nM, RPMI8226 cells: EC50=0.45nM) with a concomitant T cell activation (H929 cells: EC50=0.21nM, MM1.R cells: EC50=0.1nM, RPMI8226 cells: EC50=0.28nM). In contrast, this antibody was unable to kill BCMA- cancer cell line (MV4-11), demonstrating the specificity of the cytotoxicity. Ab-957 also inhibited tumor development or growth in two BCMA+ MM murine xenograft models inoculated with human T cells. Furthermore, this antibody could deplete BCMA+ cells in bone marrow samples from MM patient's in an ex-vivo assay with an average EC50 value of 2.5 nM. Lastly, Ab-957 is well-tolerated in cynomolgus monkey and is being developed for Phase I clinical trial in patients with multiple myeloma. Disclosures Pillarisetti: Janssen: Employment. Baldwin:Janssen: Employment. Babich:Janssen: Employment. Majewski:Janssen: Employment. Barone:Janssen: Employment. Li:Janssen: Employment. Zhang:Janssen: Employment. Chin:Janssen: Employment. Luistro:Janssen: Employment. Mendonça:Janssen: Employment. Nanjunda:Janssen: Employment. Rudnick:Janssen Pharmaceuticals R&D: Employment. Bellew:Janssen: Employment. Elsayed:Janssen: Employment, Other: stock options. Attar:Janssen: Employment. Gaudet:Janssen Pharmaceuticals R&D: Employment, Other: Stock options, Patents & Royalties: pending, not yet issued.

AML is a cancer of the myeloid lineage that is characterized by the accumulation of abnormal white blood cells in the bone marrow and blood. Existing therapies do not lead to cures, partially due to their inability to eliminate residual leukemic stem cells (LSCs) in the bone marrow. T-cell redirection has been shown to be an effective method of treatment for hematologic malignancies (eg, blinatumomab) and represents an attractive approach to treat AML. CD123 (α-chain of the interleukin-3 receptor) has been shown to be expressed on the surface of AML blasts and LSCs. To eradicate CD123+ cells, we developed a bispecific antibody (JNJ-63709178) using the Genmab DuoBody® technology that can bind both CD123 on tumor cells and CD3 on T cells. JNJ-63709178 is a humanized IgG4 bispecific antibody with silenced Fc function. This antibody is able to recruit T cells to CD123-expressing tumor cells and induce the killing of these tumor cells in vitro (MOLM-13, OCI-AML5 and KG-1; EC50 = 0.51-0.91 nM). In contrast, this antibody does not kill CD123- cell lines, demonstrating the specificity of cytotoxicity. Consistently, the degree of cell killing correlated with the level of T-cell activation (CD69 and CD25) and cytokine release (TGF-β and TNF-α). Control bispecific antibodies containing a null arm (viral epitope) paired with a CD123 arm (CD123xnull) or a CD3 arm (nullxCD3) did not induce cytotoxicity or T-cell activation in the assays tested. JNJ-63709178 had no effect on T-cell activation when incubated with T cells alone. In AML murine xenograft models, JNJ-63709178 was able to suppress tumor growth and induce tumor regression (MOLM-13 and KG-1, respectively) in the presence of human peripheral blood mononuclear cells (PBMCs) or T cells. Tumor regression correlated with the infiltration of T cells in the tumor and the expression of T-cell activation markers such as CD25, PD1 and TIM3. Furthermore, this antibody was able to induce the killing of primary CD123+ cancer cells from the blood of patients with AML without the need to supplement with fresh T cells (EC50 = 0.83 nM). These results indicate that JNJ-63709178 can potently and specifically kill CD123+ cancer cells in vitro, in vivo and ex vivo. Pharmacokinetic studies in cynomolgus monkeys support twice weekly dosing for human studies. JNJ-63709178 is currently being investigated in a Phase 1 clinical trial in relapsed and refractory AML (ClinicalTrials.gov ID: NCT02715011). Disclosures Gaudet: Janssen Pharmaceuticals R&D: Employment, Other: Stock options, Patents & Royalties: pending, not yet issued. Nemeth:Janssen Pharmaceuticals R&D: Employment, Other: stock, Patents & Royalties: patent pending. McDaid:Janssen Pharmaceuticals Research and Development: Employment. Li:Janssen: Employment. Harman:Janssen Pharmaceuticals R&D: Employment. Millar:Janssen Pharmaceuticals R&D: Employment, Other: stock options. Teplyakov:Janssen Pharmaceuticals R&D: Employment. Wheeler:Janssen Pharmaceuticals R&D: Employment. Luo:Janssen Pharmaceuticals R&D: Employment. Tam:Janssen Pharmaceuticals R&D: Employment, Other: stocks, Research Funding. Wu:Janssen Pharmaceuticals R&D: Employment. Chen:Janssen Pharmaceuticals R&D: Employment. Rudnick:Janssen Pharmaceuticals R&D: Employment. Chu:Janssen Pharmaceuticals R&D: Employment. Hughes:Janssen Pharmaceuticals R&D: Employment. Luistro:Janssen: Employment. Chin:Janssen: Employment. Babich:Janssen: Employment. Kalota:Janssen Pharmaceuticals R&D: Employment, Other: stock. Singh:Janssen Pharmaceuticals R&D: Employment, Other: stock options. Salvati:Janssen Pharmaceuticals R&D: Employment, Other: stock options, Patents & Royalties: patent. Elsayed:Janssen: Employment, Other: stock options. Attar:Janssen: Employment.

Redirecting T cells to specifically target and kill malignant cells has been validated as an effective anti-cancer strategy in the clinic with the approval of CD19xCD3 BiTE (Blincyto) for acute lymphoblastic leukemia. However, the immunosuppressive nature of the tumor microenvironment potentially poses a significant hurdle to T cell therapies. For instance, the bone marrow (BM) niche is appreciated to be a site of immune privilege at steady state to allow for normal hematopoiesis and immune cell generation. Additionally, in hematological malignancies, the BM niche is protective to leukemic stem cells, a phenomenon that has minimized the efficacy of several anti-cancer drugs including chemotherapy, targeted small molecule inhibitors and antibody based therapies. In this study, we investigated the impact of the BM microenvironment on T cell redirection. Using antibodies made with the Genmab DuoBody® technology targeting specific tumor antigens (CD123 and BCMA) and CD3, we observed that co-culture of acute myeloid leukemia (AML; KG-1, MOLM-13 and OCI-AML5) or multiple myeloma (MM; H929 and RPMI8226) cell lines with bone marrow stromal cell lines (HS-5 and HS-27a) significantly protected leukemic cells from DuoBody®-T cell mediated lysis in vitro. Specifically, co-culture of bone marrow stromal cells in killing assays led to a 20-50% decrease in the maximum observed cytotoxicity and a 3-10 fold weaker EC50, reflecting an impact on both the efficacy and potency of bispecific DuoBody® antibodies. Similar results were also observed with primary stromal cells obtained from healthy donors. Furthermore, presence of stromal cells in a humanized xenograft AML model attenuated tumor growth inhibition (TGI) observed with DuoBody® treatment (78% TGI with MOLM-13 vs 15% TGI with MOLM-13+HS-5). Impaired TGI correlated with reduced T cell activation (7 fold decrease in CD25 upregulation) and production of granzyme B (8 fold reduction), providing one potential mechanism to explain loss of activity of the DuoBody® antibody. In vitro trans-well redirection assays revealed that cell-cell contact with stromal cells was crucial for reduced T cell activation and target cell survival relative to controls. Additionally, leukemic cells not killed by T cells were observed to preferentially cluster around stromal cells. We propose that target cells can evade T cell death by a stromal cell dependent mechanism involving activation of multiple pro-survival and anti-apoptotic pathways in leukemic cells in addition to suppressed activation of T cells. We are currently studying pathways mediating the cross-talk between cancer, immune and stromal cells. A better understanding of the mechanisms underlying the protective and immunosuppressive nature of the BM microenvironment will be instrumental to the design of more effective CD3 redirected therapeutics or novel combinatorial regimens for robust anti-cancer responses. Disclosures Nair-Gupta: Janssen: Employment. Rudnick:Janssen Pharmaceuticals R&D: Employment. Luistro:Janssen: Employment. Chin:Janssen: Employment. Smith:Janssen Research & Development, LLC: Employment, Equity Ownership. McDaid:Janssen Pharmaceuticals Research and Development: Employment. Li:Janssen: Employment. Pillarisetti:Janssen Research and Development, LLC: Employment. Baldwin:Janssen: Employment. Packman:Janssen: Employment. Elsayed:Janssen: Employment. Attar:Janssen: Employment. Gaudet:Janssen Pharmaceuticals R&D: Employment, Other: Stock options, Patents & Royalties: pending, not yet issued.

AML is a heterogeneous disease characterized by uncontrolled clonal expansion of leukemic stem cells (LSCs). Current therapies for AML are not curative, in part due to their inability to eradicate LSCs from the bone marrow. T cell redirection has been shown to be effective in heme malignancies and represents a promising approach to treat AML by targeting markers differentially expressed on the cell surface of cancer cells. One marker, CD123 (α-chain of the interleukin-3 receptor) is often present on AML LSCs and blasts. We developed a human bispecific antibody (CD123xCD3; Ab-178) capable of binding to the extracellular domain of CD123 and the ϵ chain of CD3 on T cells to induce T cell–mediated tumor cell killing. This bispecific IgG4 antibody can recruit T cells to CD123+ AML cells (MOLM-13, KG-1 and OCI-AML5) and induce T cell activation as evidenced by CD69 and CD25 up-regulation on T cells. Ab-178 potently killed these CD123+ AML cell lines in vitro (EC50 = 0.51-0.91 nM) but not a CD123− cell line (JIM3). Ab-178 was also able to induce tumor inhibition (MOLM-13 cells) and regression (KG-1 cells) in murine xenograft CD123+ AML models in the presence of human PBMCs. Furthermore, this antibody was able to kill AML blasts in primary AML blood samples ex vivo in the absence of exogenous T cells (autologous setting; EC50 = 0.83 nM). Related bispecific antibodies directed against a viral epitope (nullxCD3 or CD123xnull) did not activate T cells or cause tumor cell killing in the various assays tested. Ab-178 had no impact on T cell activation when incubated with T cells alone. These results indicate that Ab-178 can potently and specifically activate T cells in the presence of CD123+ AML cells and induce their killing. Furthermore, because of the antibody format, this molecule is expected to have a longer half-life compared to smaller bispecific biologic scaffolds. Ab-178 is currently being evaluated pre-clinically for its potential to treat patients with AML. Citation Format: Francois Gaudet, Jennifer F. Nemeth, Ronan McDaid, Yingzhe Li, Benjamin Harman, Hillary Millar, Alexey Teplyakov, John Wheeler, Jinquan Luo, Susan Tam, Sheng-Jiun Wu, Emily Chen, Alexander Babich, Yusri Elsayed, Ricardo Attar. Development of a CD123xCD3 bispecific antibody to treat acute myeloid leukemia (AML). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1492.

To determine the maximum tolerated dose (MTD) of trabectedin plus gemcitabine administered on a weekly schedule in patients with advanced solid tumors.Patients with ECOG performance status 0-1 and adequate organ function were enrolled. On days 1, 8, and 15 of a 28-day cycle, patients received gemcitabine (starting dose, 800 mg/m(2)) followed by trabectedin (starting dose, 0.3 mg/m(2)). Strict liver function test treatment criteria were employed to avoid hepatic toxicity seen in previous trabectedin studies. Plasma samples were collected during cycles 1 and 2 for pharmacokinetic analyses.Fifteen patients receivedor=1 dose, with a median of two treatment cycles (range 1-10). The most common drug-related toxicity was hepatic. Dose reductions were required for trabectedin in four (27%) patients and gemcitabine in six (40%) patients. Cycle delays/dose holds were required in 11 (73%) patients and doses above trabectedin 0.4 mg/m(2) and gemcitabine 1,000 mg/m(2), which is the recommended phase II dose, were not feasible. Seven patients maintained stable disease after two cycles. Gemcitabine and trabectedin pharmacokinetics were not altered substantially with concomitant administration.Given the lack of pharmacokinetic interaction and potential efficacy of trabectedin and gemcitabine combination therapy, further study is warranted with alternate schedules.

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Background: JNJ-42756493 is an FGFR 1, 2, 3, and 4 inhibitor with nanomolar affinity, orally bioavailable, and has demonstrated a broad spectrum antitumor activity in cell line, xenograft and patient-derived explant models with abnormality in FGFR signaling pathway such as FGFR gene amplification, mutation and translocation. Methods: A multipart phase 1 first in human study of JNJ-42756493 was initiated in advanced solid tumor patients ([NCT01962532][1]) including, Part 1 dose-escalation to determine the recommended phase 2 dose (RP2D) based on safety, pharmacokinetic, and pharmacodynamic data; Part 2 biopsy cohort to confirm the RP2D and Part 3 expansion phase to evaluate anti-tumor activity in NSCLC, SCLC, Breast cancer and other solid tumor patients with FGFR gene amplification, mutation or translocation at RP2D. Multiple biomarkers from tissue (including phospho-FGFR, phospho-Erk and phospho-S6) and serum (phosphate, calcium, Vitamin D, PTH and FGF23) were also assessed in the study. Results: At data cut-off (22 October 2013), total of 28 patients had been treated at 5 dose levels (0.5, 2, 4, 6 and 9 mg daily continuously) in Part 1 of the study. JNJ-42756493 appeared safe, did not generate any dose-limiting toxicities or any drug related severe adverse events. One patient from 4 mg cohort died after receiving 6 doses in Cycle 1, autopsy indicated a serious adverse event (SAE) of pulmonary edema which not related to the study drug. The most common adverse events (AEs) were hyperphosphatemia (57%), asthenia (46%), dry mouth (32%), abdominal pain (29%), diarrhea (25%), vomiting (25%), decreased appetite (21%) and constipation (21%). Grade 1 or 2 hyperphosphatemia was managed by co-administration of phosphate lowering therapy and by treatment interruption, other AEs were generally mild to moderate. No clinically significant cardiac safety findings were observed. Pharmacokinetics was linear and predictable with a half-life of ∼50 hours. Dose levels ≥ 6mg achieved plasma concentrations predicted to be efficacious from preclinical experiments. Dose dependent changes in biomarkers including increases in phosphate, FGF23 and calcium and decreases in PTH were observed in blood, evaluation of biomarker response in tissue is ongoing. A bladder cancer patient with lung metastasis harboring a FGFR3-TACC3 translocation treated at 9 mg had a confirmed PR. 9 mg was declared as the first RP2D, but safety evaluation of JNJ-42756493 at higher doses is ongoing. Conclusions: JNJ-42756493 has excellent pharmaceutical properties and appeared safe with manageable side effects at dose levels that elicit anti-tumor activity. Citation Format: Rodrigo Dienstmann, Rastilav Bahleda, Barbara Adamo, Jordi Rodon, Andrea Varga, Anas Gazzah, Suso Platero, Hans Smit, Timothy Perera, Bob Zhong, Kim Stuyckens, Yusri Elsayed, Chris Takimoto, Vijay Peddareddigari, Josep Tabernero, Feng Roger Luo, Jean-Charles Soria. First in human study of JNJ-42756493, a potent pan fibroblast growth factor receptor (FGFR) inhibitor in patients with advanced solid tumors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT325. doi:10.1158/1538-7445.AM2014-CT325 [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01962532&atom=%2Fcanres%2F74%2F19_Supplement%2FCT325.atom

Abstract 3676 Background Mycosis fungoides (MF) and Sézary syndrome (SS) represent two major instances of cutaneous T-cell lymphoma (CTCL), which are incurable and have shown response to treatment with histone deacetylase (HDAC) inhibitors. Quisinostat is a potent and orally active HDAC inhibitor that has been found to be active in preclinical models and phase 1 trials. The purpose of this phase 2 trial (NCT01486277) is to evaluate the efficacy and safety of quisinostat in patients with previously treated advanced stage IB-IVA MF or SS. Patients and Methods Patients with relapsed or refractory, measurable, histopathologically confirmed CTCL, stages IB to IVA MF/SS, were treated with 8mg or 12 mg of oral quisinostat on days 1, 3 and 5 of each week in a 21-day treatment cycle. Patients who were initially randomized to the 8 mg dose cohort and did not have evidence of disease progression were allowed to have their dose increased to 12 mg. The primary efficacy endpoint was the overall cutaneous response rate (RR) measured by the modified Severity Weighted Assessment Tool (mSWAT). Key secondary endpoints included overall global RR, progression-free survival (PFS), 1-year overall survival (OS) rate, duration of response (DOR), and patient-reported outcome (PRO) which included the European Organization for Research and Treatment of Cancer Core (EORTC) questionnaire QLQ-C30 and the Pruritus Intensity Assessment questionnaire. Other secondary endpoints were pharmacodynamic markers, biomarkers predictive of response, and population pharmacokinetics (PK). Safety and tolerability have also been evaluated. Results Twenty-six patients were enrolled, including 6 patients in the 8 mg dose group and 20 patients in the 12 mg dose group. One patient in the 12 mg dose group discontinued prematurely from the study due to investigator's decision, and was therefore excluded from the response evaluable analysis set. Overall, enrolled patients included 81% male; median age = 61 years (range 32–80 years); 96% white; MF/SS stage: IB/IIA = 35% (n=9) and IIB/III/IVA = 65% (n=17); CTCL type: MF = 96% (n=25), and SS = 4% (n=1); mean Pruritus Intensity Score = 5.1. The preliminary results of this ongoing trial have shown that 6 out of 19 patients (31.6%) in the 12 mg dose group achieved ≥ 50% reduction in mSWAT score at least once, with confirmed response in the skin in 4 patients (1 complete response (CR) and 3 partial response (PR); overall RR = 21.1% with 95% CI: 6.1% to 45.6%). For the other 2 patients, the confirmation of response is pending in 1 patient and the other patient stopped the treatment due to non-drug related adverse event (AE). Nine patients are still on the treatment with the 12 mg dose, and 11 patients have discontinued the drug (6 due to progressive disease (PD), 2 due to investigator's decision, 2 due to AE, and 1 due to death). In the 8 mg dose group, no CR or PR in the skin has been observed, and 4 out of 6 patients have discontinued due to PD. The secondary endpoint results of overall global RR, PFS, 1-year OS rate, DOR, and PROs, as well as biomarker results for AcH3, ac-Tubulin, Cleaved Caspase 3, HR23B and pStat3, will be presented when further analysis results are available. To date, the most common (≥ 5% of patients) drug-related AEs have been nausea (23%), diarrhea (19%), asthenia (12%), thrombocytopenia (12%), hypertension (8%), lethargy (8%), palpitations (8%), pruritus (8%) and vomiting (8%); most of them were grade 2 or lower in severity. Grade 3 or higher AEs included hypertension (4%), lethargy (4%), pyrexia (4%), and hyperkalaemia (4%). One patient in the 8 mg dose group has required dose reduction due to hypertension. The efficacy and safety results from the final analysis will be presented. Conclusion Preliminary results indicate that oral quisinostat at 12 mg dose on a 3 times weekly schedule is active in the treatment of patients with relapsed or refractory MF/SS not previously treated with an HDAC inhibitor, and has an acceptable safety profile. Disclosures: Child: Cephalon UK : Honoraria; Janssen R&D: Research Funding. Ortiz Romero:Ferrer Farma SA: Honoraria; Eisai: Honoraria. Weichenthal:Merck Inc.: Consultancy, Honoraria. Bernengo:Janssen R&D: Research Funding; NOVARTIS: Research Funding. Pérez Ferriols:Pfizer: Consultancy, Honoraria, Research Funding. Hellemans:Janssen R&D: Employment, Equity Ownership. Elsayed:Janssen R&D: Employment, Equity Ownership. Phelps:Janssen R&D: Employment, Equity Ownership. Forslund:Janssen R&D: Employment. Kamida:Janssen R&D: Employment. Zinzani:Millennium Takeda: Consultancy; Celgene: Consultancy.

Background The randomized phase 3 LYM3001 trial in relapsed follicular lymphoma (FL) demonstrated higher overall (ORR) and complete response (CR) rates and prolonged progression-free survival (PFS) with bortezomib-rituximab versus rituximab. We report findings in high-risk patients (FL International Prognostic Index [FLIPI] score ≥3, and high tumor burden by modified Groupe d’Etude des Lymphomas Folliculaires [GELF] criteria). Methods Patients aged ≥18 years with grade 1/2 FL, ≥1 measurable lesion, and documented relapse or progression following prior therapy, rituximab-naïve or rituximab-sensitive, were enrolled at 164 centers in 29 countries across Europe, the Americas, and Asia-Pacific. Patients were randomized (1:1) to five 5-week cycles of bortezomib-rituximab (bortezomib 1.6 mg/m2, days 1, 8, 15, and 22, all cycles; rituximab 375 mg/m2, days 1, 8, 15, and 22, cycle 1, and day 1, cycles 2–5; N=336) or rituximab alone (N=340). Randomization was stratified by FLIPI score, prior rituximab, time since last dose of anti-lymphoma therapy, and geographical region. The primary endpoint of the study was PFS. Results 103 bortezomib-rituximab and 98 rituximab patients had high-risk FL. The ORR was 59% versus 37% (p=0.002), the CR/CRu rate was 13% versus 6% (p=0.145), and the durable response rate was 45% versus 26% (p=0.008) with bortezomib-rituximab versus rituximab. Median PFS was 9.5 versus 6.7 months (hazard ratio [HR] 0.667, p=0.012) with bortezomib-rituximab versus rituximab; median time to progression was 10.9 versus 6.8 months (HR 0.656, p=0.009); median time to next anti-lymphoma treatment was 14.8 versus 9.1 months (HR 0.762, p=0.103); and the 1-year Overall Survival rate was 83.1% versus 76.6%. Overall, 51% of bortezomib-rituximab and 32% of rituximab patients reported grade ≥3 adverse events, including neutropenia (18%, 6%), anemia (4%, 5%), diarrhea (8%, 0%), thrombocytopenia (5%, 2%), and sensory neuropathy (1%, 0%). Conclusions High-risk FL patients treated with bortezomib-rituximab had significantly higher ORR and longer PFS than patients receiving rituximab alone, with greater clinical benefit than in the overall study population; additional toxicity was acceptable and did not affect treatment feasibility. Trial registration The phase 3 LYM3001 trial is registered with ClinicalTrials.gov, with the identifier NCT00312845.

3059 Background: CC-chemokine ligand 2 (CCL2) is expressed in various malignancies, implicated in angiogenesis, proliferation and metastasis. CNTO888 is a hIgG1κ mAb with selective high CCL2 binding affinity and showed preclinical antitumor activity. Methods: Primary objectives were safety and a recommended dose of CNTO 888 in combination with chemotherapy: Arm 1 - 15 mg/kg CNTO 888 + docetaxel 75 mg/m2 Q3W; Arm 2 - 15 mg/kg CNTO 888 + gemcitabine 1000 mg/m2 on D1 and 8 Q3W; Arm 3 - 15 mg/kg CNTO 888 + paclitaxel 175 mg/m2 and carboplatin AUC6 Q3W; Arm 4 - 10 mg/kg CNTO 888 Q2W + pegylated doxorubicin 50 mg/m2 Q4W. Two (Arms 1, 2, 3) or 4 (Arm 4) prior chemotherapies for advanced disease were allowed. Pharmacokinetic (PK) profile of CNTO 888 and chemotherapies, free and total CCL2, CTC/CEC count, and uNTX were evaluated. Adverse events (AE) and dose limiting toxicities (DLT) were evaluated after 6 subjects completed 1 cycle. Results: 53 subjects (22F/31M) were treated: Arm 1 n=15, Arm 2 n=12, Arm 3 n=12, Arm 4 n=14. Two DLTs occurred: a grade 4 febrile neutropenia (Arm 1) and a grade 3 neutropenia (Arm 2). All 4 combinations were found to be safe and tolerable and continued enrolment to a minimum of 12 subjects evaluable for safety and PK. Best overall response were partial response (PR) (1) and stable disease (18; 2 ≥ 4 months). One subject with pancreatic adenocarcinoma achieved PR, allowing for surgical resection. Most frequently reported (≥ 20%) related serious AEs are: Arm 1: Neutropenia, Stomatitis, Fatigue, Febrile neutropenia, Alopecia. Arm 2: Anemia. Arm 3: Thrombocytopenia, Alopecia, Neutropenia, Asthenia, Fatigue, Anemia, Arthralgia, Nausea, Vomiting. Arm 4: Stomatitis, Rash, Fatigue, Nausea, Anemia, Neutropenia. CNTO 888 did not affect the chemotherapy PK profile; similarly, chemotherapy did not affect the CNTO 888 PK profile. No subjects (n=38) tested positive for antibodies to CNTO 888. Free CCL2 declined 2 hrs post treatment and returned to baseline levels by 48 hrs and continued to increase with further administrations in all treatment arms. There were no consistent changes with other biomarkers. Conclusions: CNTO 888 in combination with standard chemotherapy was well tolerated but few objective responses were seen.

Abstract 265 Background: Treatment goals in patients with relapsed FL are to prolong PFS and improve overall survival (OS). To optimize treatment for individual patients, identification of subgroups most likely to benefit from a specific therapy is important. The international, randomized, phase 3 LYM3001 study in patients with relapsed or refractory FL demonstrated improved PFS with bortezomib-rituximab vs rituximab alone (median 12.8 vs 11.0 months, HR 0.822, p=0.039), plus increased overall response rate (ORR; 63% vs 49%, p=0.0004), complete response rate (CR/CRu; 25% vs 18%, p=0.035), and durable (≥6 months) response rate (50% vs 38%, p=0.002) in an unselected patient population. Here we present exploratory biomarker analyses aimed at identifying patient subgroups deriving a longer PFS benefit with bortezomib-rituximab and showing a trend for better OS. Methods: Patients received five 5-week cycles of bortezomib-rituximab (N=336) or rituximab (N=340). Response was assessed using modified International Working Group response criteria. Archived tumor tissue was collected at baseline from 502 (74%) patients; whole blood samples for germ-line DNA were collected on day 1 of cycle 1 from 619 (92%) patients. Protocol-specified candidate biomarkers were based on associations with bortezomib (NF-κB p65, PSMA5, p27, PSMB1/5/8/9) or rituximab (CD68, FCGR2A/3A) activity. Immunohistochemistry assays were used for protein analysis. Taqman SNP assays and PCR/LDR were used for genotyping. Statistical analyses included single-marker analyses, pair-wise combination analyses (n=1140 comparisons), and multiple comparison analyses of all evaluable patients in LYM3001. Clinical covariates included in the analysis were baseline FLIPI score, prior rituximab, time since last anti-lymphoma therapy, region, age, gender, race, Ann Arbor stage, high tumor burden, and number of prior lines of therapy. Results: Single markers and biomarker pairs (n=102) highlighted patient subsets that had significantly improved outcomes with bortezomib-rituximab vs rituximab. For 14 of the pairs, the PFS benefit was ≥6 months. Using false discovery rate (FDR) to control for multiple comparison corrections, one biomarker pair was significant. This pair (presence of the PSMB1 P11A C/G heterozygote, and low CD68 expression [0–50 CD68-positive macrophages in the follicular space]) was associated with significantly improved PFS in patients receiving bortezomib-rituximab vs rituximab (median 16.6 vs 9.1 months, HR 0.407, p2 prior lines of therapy). There was also a trend towards an OS benefit (medians not reached, HR 0.426, p=0.0550), as well as a significantly higher ORR (73.7% vs 47.5%, p=0.0077), a higher CR rate (33.3% vs 23%, p=0.3044), and a significantly longer time to next therapy (median 33.1 vs 14.8 months, p=0.0013). In patients lacking this biomarker pair (N=238) no significant efficacy differences were seen. No other similar studies were available to confirm the reproducibility of these analyses. Therefore, we split the LYM3001 dataset into discovery and confirmation cohorts (7:3 ratio of biomarker-evaluable patients) to enable evaluation and confirmation in independent cohorts of patients The significant biomarker pair of PSMB1 P11A C/G heterozygote and low CD68 was identified in the discovery cohort (N=198) with a PFS advantage with bortezomib-rituximab vs rituximab of 5.7 months (median 14.2 vs 8.4 months, p=0.0003) and an indication of longer OS (HR 0.47, p=0.1291). This biomarker pair also showed a clear PFS advantage in the confirmation cohort (N=108, 8.7-month PFS benefit; median 18.2 vs 9.5 months, HR 0.44, p=0.0817). Other significant biomarker combinations, including combinations of molecular and clinical variables (e.g. high tumor burden) were identified and will be presented. Conclusions: Analyses of the phase 3 LYM3001 trial identified biomarker combinations present in a third of patients offering a significant PFS benefit with bortezomib-rituximab vs rituximab. Use of such biomarker assays in patients with relapsed or refractory FL may aid identification of subgroups deriving maximal benefit from the addition of bortezomib to rituximab therapy. Disclosures: Coiffier: Janssen-Cilag: Consultancy; Roche: Consultancy; Amgen: Consultancy; Sanofi: Consultancy; Pfizer: Consultancy; Millennium Pharmaceuticals, Inc.: Consultancy; Celgene: Consultancy; Pharmacyclics: Consultancy; MedImmune: Consultancy; CTI: Consultancy. Off Label Use: Bortezomib used in combination with rituximab in patients with relapsed/refractory follicular lymphoma. Li:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Henitz:Janssen Research & Development: Employment. Karkera:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Favis:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Gaffney:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Shapiro:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Theocharous:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Elsayed:Janssen Research & Development: Employment; Johson & Johnson: Equity Ownership. de Velde:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Rule:Johnson & Johnson: Advisory Board, Institutional grant, meeting attendance expenses, Honoraria. Walewski:Janssen-Cilag: Institutional/personal grants, advisory board; Hoffman La Roche: Honoraria, Institutional/personal grants, travel/accommodation expenses; Mundipharma: Honoraria; Celgene: Honoraria. de Vos:Millennium Pharmaceuticals, Inc: Consultancy. Crump:Janssen/Ortho-Biotech: Consultancy. Shpilberg:Janssen-Cilag: Consultancy, Honoraria. Cakana:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership. Esseltine:Millennium Pharmaceuticals, Inc: Employment; Johnson & Johnson: Equity Ownership. Mulligan:Millennium Pharmaceuticals, Inc.: Employment. Ricci:Janssen Research & Development: Employment; Johnson & Johnson: Equity Ownership.

Background: HDACi have demonstrated activity as anticancer agents and are licensed for use in cutaneous and peripheral T cell lymphoma. Cardiac effects including arrhythmias and QTc prolongation have previously been associated with HDACi administration in humans. This report summarizes the cardiac adverse event (AE) profile observed during the recently completed FIH Phase I trial of JNJ26481585. Methods: Continuous oral daily dosing (QD) of JNJ26481585 in 21-day (D) cycles (C) was investigated initially in 20 patients (pts) demonstrating activity (including 1 partial response, 1 minor response, 1 prolonged stable disease in melanoma) but ventricular arrhythmia (2 pt) and fatigue (1 pt) were dose-limiting. To improve tolerability, 3 intermittent schedules (QD Mon/Wed/Fri (MWF); QD Mon/Tue/Wed/Thu (MTWT); QD Mon/Thu (MT)) also in 21-D C were subsequently explored in 38 (including expansion cohort), 19 and 15 pts respectively. All pts had triplicate 12-lead ECG (tECG), 24 hour ECG (Holter) and echocardiography or MUGA scan for assessment of left ventricular ejection fraction (LVEF) at baseline and during treatment. Analysis of mean QTcF, categorical QTcF and preliminary assessment of cardiac rhythm/morphology was performed. Results: 12mg QD MWF was identified as the recommended Phase II dose (RP2D) based on safety, tolerability, PK predictions and PD activity. Maximum average increase in mean QTcF from baseline ranged from 0 to 8 milliseconds (ms) during cycles 1 and 2 across the 4 schedules. At RP2D, the maximum average increase in mean QTcF observed was 6ms. 1 out of 38 pts (2.6%) treated on the MWF schedule experienced a Grade (G) 3 QTcF prolongation, possibly related to ST-T segment changes identified as a class effect of HDACi. QTcF prolongation G1–2 was rarely observed across schedules and mostly occurred as an isolated reversible observation whilst on study drug. Reversible, non-sustained ventricular tachycardia (NSVT) was observed as a dose limiting toxicity (DLT) in 3 out of 39 pts (7.7%) receiving QD or MTWT dosing but was not observed on the MWF or MT schedules. Other reversible, but dose-limiting, cardiac effects were T-wave inversion (2 pts on MT and MTWT), supraventricular tachycardia (1 pt on MT) and hypertension with raised troponin (1 pt on MWF). Non-specific, reversible, asymptomatic ST-T segment changes were frequently observed. LVEF was unaffected during treatment with JNJ26481585. Conclusion: The RP2D of JNJ26481585 was determined as 12 mg on the MWF schedule and demonstrated an acceptable cardiac safety profile. One pt had QTcF>500 ms but no clinically significant effect on the QTcF interval was observed across schedules. Reversible NSVT was identified as a DLT in some patients on the QD and MTWT dosing schedules but not on the MWF and MT schedules. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A164.

Background: Despite the large numbers of antibodies targeting soluble ligands in development in oncology and other therapeutic areas, very few reports have described pharmacodynamic (PD)/ mechanism of action (MOA) biomarkers of free ligand or total (antibody-complexed) ligand and their PK-PD relationship. Carlumab is a human IgG1 monoclonal antibody that binds the chemokine CCL2, which is a potent chemoattractant for tumor associated macrophages and promotes tumor growth and metastasis. Therapeutic targeting of CCL2 was based on the hypothesis that carlumab binding would inhibit chemokine activity and block tumor inflammation and macrophage differentiation thereby impairing tumor growth and metastases. Because proof of concept (POC) is a major milestone in early drug development, the objective of this study was to develop key PD/MOA biomarkers to facilitate the clinical evaluation of POC for carlumab. This required the development of robust analytical assays to accurately measure free and total CCL2 concentrations in the serum, and mechanistic PK-PD modeling for data analysis. Methods: Carlumab was evaluated in three oncology clinical studies (as monotherapy in a Phase 1 first-in-human trial in patients with solid tumors, a Phase 1b chemotherapy combination study, and as a single agent Phase 2a study in patients with advanced prostate cancer). Biomarkers evaluated included free and total CCL2 concentrations in serum, a broad panel of soluble biomarkers, bone turnover markers, and circulating tumor cell (CTC) enumeration. Sequential tumor biopsies in ten patients from Phase 1 study yielded 4 paired specimens for immunohistochemical analysis of tumor associated macrophages (TAMs). A mechanistic PK-PD model that simultaneously characterized free and total CCL2, and carlumab concentrations in serum was used to estimate biologically effective doses that would inhibit CCL2 signaling. Results: Analysis of CCL2 levels following carlumab administration revealed a rapid fall in free CCL2 as expected; however, post-treatment free CCL2 levels rapidly rebounded and quickly exceeded pretreatment serum concentrations. Two different analytical methods showed that carlumab suppressed CCL2 levels for only ∼24 hrs followed by a sustained increase in CCL2 concentration with subsequent treatment. These surprising results suggest that carlumab was ineffective at neutralizing free CCL2. PK-PD modeling confirmed the transient suppression of free CCL2 consistent with a higher carlumab dissociation constant (Kd) for CCL2 binding in vivo. Finally, carlumab did not affect other biomarkers including bone turnover markers or CTC numbers, consistent with an inability to impact CCL2 signaling. No evidence of clinical efficacy was observed in any of carlumab clinical trials. Conclusion: Development of robust analytical assays to measure free and total CCL2 concentration and utilization of mechanistic PK-PD modeling facilitated the clinical evaluation of POC for carlumab. The unexpected increase in free CCL2 concentration and the lack of CCL2 target suppression likely explain the absence of carlumab clinical activity. Supportive biomarker analyzes and mechanistic PK-PD modeling are important components of the early development clinical plan for developing biologics against soluble ligands. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A37.

Abstract 857 Background: Follicular lymphoma (FL) is an incurable B-cell non-Hodgkin's lymphoma (NHL) representing ∼20% of all NHL. Rituximab (R) is approved for the treatment of CD20+ relapsed/refractory FL, and single-agent bortezomib (Vc; VELCADE®) has shown activity in heavily pretreated patients. Vc and R show additive activity in preclinical models, and the combination was active and well tolerated in a phase 2 study. This randomized, open-label, multi-center, international, phase 3 clinical trial (LYM3001) compared the efficacy and safety of Vc plus R (Vc-R) vs R alone in patients with relapsed or refractory, R-naive or R-sensitive FL. Methods: Patients with grade 1/2 measurable FL who had relapsed/progressed following prior therapy (time to progression [TTP] ≥6 months if prior R-containing therapy), ECOG performance status ≤2, and no peripheral neuropathy grade ≥2 were randomized (1:1) to receive 5-week cycles of Vc-R (Vc 1.6 mg/m2, d 1, 8, 15, 22, cycles 1–5, plus R 375 mg/m2, d 1, 8, 15, 22 in cycle 1 and d 1 only in cycles 2–5) or R alone (administered according to the same schedule as for the Vc-R arm). In both groups, treatment was administered for five cycles or until progression or unacceptable treatment-related toxicity. Randomization was stratified by FLIPI score (0–1 vs 2 vs ≥3), prior R therapy (yes vs no), time since last dose of anti-FL therapy (≤1 vs >1 year), and region (US vs EU vs rest of world). Primary endpoint was progression-free survival (PFS); secondary endpoints included overall response rate (ORR), complete response (CR) rate, TTP, and safety/tolerability. Response and progression were assessed by independent radiology committee (IRC) using the modified International Workshop Response Criteria. Planned sample size was 670 patients to provide 90% power (α=0.05, 2-sided) to detect a 33% improvement in median PFS with Vc-R vs R (i.e. 13.3 vs 10 months). Results: Between April 2006 and August 2008, 676 patients (intent-to-treat [ITT] population) were enrolled from 164 centers in 29 countries across Europe, the Americas, and Asia. Baseline characteristics were well balanced between the two arms; median age was 57 years (range 21–84), 54% were female, 75% were Caucasian and 21% were Asian. The majority of patients (93%) had an ECOG performance status of 0 or 1, 51% and 48% had grade 1 and 2 FL, respectively, and 41%, 35%, and 23% had high, intermediate, and low FLIPI score, respectively; 83% had Ann Arbor Stage III or IV, and 38% had bone marrow involvement at baseline. 33% of patients had received 3 or more prior lines of therapy (range 1–6+); 44% had received prior R therapy. The most common prior regimens were CHOP (38%), CVP (25%), single-agent R (17%), R-CHOP (12%), and R-CVP (11%). At a median follow-up of 33.9 months, a total of 440 PFS events were observed by IRC in the ITT population, 212 in the Vc-R arm and 228 events in the R arm. Median PFS improved from 334 days (95% CI: 278, 365) with R alone to 389 days (95% CI: 351, 456) with Vc-R; the hazard ratio was 0.822 (95% CI: 0.681, 0.991). This improvement is statistically significant with a 2-sided P-value of 0.039. The ORR was 63% with Vc-R vs 49% with R (P6 months) was 50% with Vc-R vs 38% with R (P=0.002). The median time to subsequent antilymphoma treatment was significantly improved in the Vc-R vs R arm (700 vs 537 days, P=0.027). Median OS was not reached in either group. Patients received a median 25 weeks treatment in both the Vc-R and R groups (range 5–40 and 5–35 in the Vc-R and R groups, respectively). Adverse events (AEs) were reported for 95% of Vc-R and 78% of R patients. The most common AEs were diarrhea (52% Vc-R, 8% R), nausea (29% Vc-R, 7% R), and pyrexia (25% Vc-R, 10% R). Most AEs were grade 1 or 2. Grade ≥3 AEs were reported in 46% of Vc-R and 21% of R patients; the most common grade ≥3 AEs were neutropenia (11% vs 4%) and diarrhea (7% vs 0%). Peripheral sensory neuropathy was reported in 17% of patients in the Vc-R arm vs 1% in the R arm; 3% vs 0% grade ≥3. 18% and 11% of Vc-R and R patients, respectively, had serious AEs, only 4% and 1% of patients discontinued due to drug-related AEs, and there were 9 and 4 on-treatment deaths, respectively. Conclusion: The addition of weekly Vc to R therapy in patients with relapsed FL was associated with statistically significant improvements in PFS, response rate, and time to next antilymphoma treatment, with acceptable additional toxicity. Disclosures: Coiffier: Johnson & Johnson: Honoraria. Off Label Use: Discussion of Velcade in NHL subtypes other than mantle cell lymphoma is included. Mayer:Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Rule:Johnson & Johnson: Consultancy, Speakers Bureau; Roche: Consultancy. Walewski:Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen-Cilag: Investigators fee. Crump:Millennium Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy. Shpilberg:Johnson & Johnson: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Hermann:Millennium Pharmaceuticals: Research Funding. Parasuraman:Millennium Pharmaceuticals: Employment, Equity Ownership. Zhu:Johnson & Johnson: Employment. Enny:Johnson & Johnson: Employment, Equity Ownership. Theocharous:Johnson & Johnson: Employment. van de Velde:Johnson & Johson: Employment, Equity Ownership. Elsayed:Johnson & Johnson: Employment, Equity Ownership.

TPS303 Background: Rituximab is routinely administered in several consecutive lines of therapy for follicular lymphoma. Although the frequency and significance of emerging rituximab resistance is n...

8050 Background: AL is characterized by deposition of monoclonal immunoglobulin light chains leading to multi-organ failure and death. B (Velcade®) is a specific inhibitor of the 26S proteasome with activity in several malignancies. This mechanism of action raises concern of enhancing the amyloidogenic protein deposition and worsening of AL. This phase I/II study is to determine the maximum tolerated dose (MTD) and toxicity profile of B in pts previously treated for AL. Secondary objectives include the rate and duration of hematologic and organ responses. Methods: A 3+3 dose escalation design was used for the phase I part. Eligibility criteria included previously treated AL with organ involvement, LVEF =40% and adequate organ function. Pts with prior B treatment, infection, significant cardiac disease, bleeding or gr. 2 neuropathy were excluded. Seven cohorts are planned to examine two administration schedules. A weekly schedule administering 0.7,1.0,1.3 or 1.6 mg/m2 of B on day 1, 8, 15, 22 of a 35-day cycle. In the bi-weekly schedule, 0.7, 1.0 or 1.3 mg/m2 are given on day 1,4,8, 11 of a 21-day cycle. Pts were assessed at specified intervals and dose-limiting toxicities (DLT) were assessed during cycle 1. Results: At this time, 15 pts were treated in the 4 weekly cohorts. Median age was 59 yrs (38–74). All pts had previously received systemic therapy; 100% had received melphalan (58% with prior SCT), 83% steroids, 58% thalidomide. 75% of pts had = 2 organs involved at baseline, renal 42%, cardiac 33%, neuropathy 33%. One DLT (worsening CHF) was observed in cohort 1.6 mg/m2. Two pts discontinued early due to CHF and hypotension. Grade 3/4 AEs were reported in 42% of pts and the most frequent were fatigue 17%, infection 17%, CHF 8% and retinal detachment 8%. The most frequent grade 1/2 AEs were diarrhea 67%, nausea 42%, fever 33%, dizziness 33% and neuropathy 8%. There were no treatment-related deaths. Of the 11 evaluable pts for response, 5 (45%) had objective hematological responses (2 CR and 3 PR) and 4 pts (36%) have stable disease > 6 months. Dose escalation on the biweekly schedule is ongoing. Conclusions: B has significant activity in patients with relapsed AL in this preliminary analysis and tolerance to B is satisfactory. The MTD for the weekly schedule is 1.6 mg/m2. Further assessment is planned in the phase II part. [Table: see text]